The present invention relates to a process and apparatus for the recovery of a compound, for example a peptide-containing compound, from a solution containing contaminants by combined affinity-chromatographic purification and ultrafiltration.
A process is described in published European patent application No. 0 046 915 which makes use of a carrier in dissolved form. A soluble complex of ligand and carrier is also disclosed in Schneider U.S. Pat. No. 4,066,505. However, because of the elongated molecular structure of the soluble carrier employed in such processes, it may slip through the pores of a membrane. Theoretically, this problem should be avoidable by using a membrane with a lower top cut-off limit, but in practice it is difficult to provide such a "tailor-made" membrane. Thus, the problem at the most can be reduced, but not totally and completely eliminated. In addition, a membrane which has such a lower top cut-off limit, i.e., within the interval appropriate in this particular context smaller than about 1.times.10.sup.6 Dalton, requires a complicated technique of manufacture and is therefore considerably more expensive than the more readily accessible membranes with a top cut-off limit around 1.times.10.sup.6 Dalton or over, e.g., up to 100.times.10.sup.6 Dalton.